RESEARCH DIRECTED TO THE DETERMINATION OF SUBSURFACE TERRAIN PROPERTIES AND ICE THICKNESS BY PULSED VHF PROPAGATION METHODS.
Abstract
A new method is described of generating V.H.F. pulses of less than 100 nanoseconds duration containing a multi-octave dispersion of frequencies. It is shown that this type of pulse is modified on reflection from layered surfaces such as soils or ice and that analysis of the reflected waveform can be used to classify target characteristics. A relatively simple method has been devised for effectively tuning at narrow band and return signals despite their very broad bandwidth and for analyzing and displaying the significant characteristics of the reflection. Preliminary results have been obtained over various types of soils and it has been shown that the measurement of dielectric constant and moisture of soils by use of monochromatic radars is not generally applicable for reasons attributed provisionally to layering effects in the soils. It is suggested that multi-frequency techniques operating in the range dominantly between 100 and 300 megacycles are required in order to achieve satisfactory results. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1965
- Accession Number
- AD0462850
Entities
People
- A. R. Barringer